Process and device for making form pieces of wood



June-ls', 1925. j 1,542,576

F. PFLEUMER PROCESS AND DEVICE FOR MAKING FORM PIECES OF WOOD Filed March 8, 1923 2 Sheets-Sheet 1 g-WHRMH Iga .1

Ziff/@Zini f2- F. PFLEUMER PROCESS AND DEVICE FOR MAKING FORM PIECES OF WOOD Filed March 8, 1923 2 sheets-sheet 2 Patented J une` 16d, 1925.

UNITED sTA Tes PATENT OFFICE.

SCI-IAP PROCESS AND DEVICE FOR AGOWMAATSCHAPPIJ TOT HET VAN HOUT, OF TER APEL (G VERWERKEN, VEREDELEN EN DROGEN ROEL), THE NETHERLANDS.

MAKING FORM PIECES or Woo-n.

Application fle'diMarch S, 1923. Serial No. 623,77'1.

To all whom t may concern:

Be it known that I, FRITZ PFLEUMER, a citizen of the Austrian Republic, residing at Dresden-A., Germany,

Bodenbacherstrasse 44, have invented certain new and useful improvements Making Form in Processes and Devices for Pieces of lVood, of which the following is a specification.

Processes for producing wood are already known.

dense masses oi' The wood 1s used in these processes while utilizing the natural cohesion of its structure and cut in blocks, plates, etc., which are compressed; this process produces a material which possesses high powers of nieehanical resistance but re quires special measures for dyeing,

impregnating, drying and pressing. In this .manner a wood substance 1s obtained whose pore cific gravity'of 1.34.45.

These processes technical diiieultie l: During the usually done especially for pro shutting up of the result in the following drying period'. This is before the pressing takes place,

cesses which require the wood for the purpose of obtaining the greatest possible compactness, as the water contents of the Wood can not be pressed out during the pressing process.

But drying vantage that the and flexibility.

Furthermore, on drying after pr before pressing has the disad Wood loses its elasticity artificially dried woods keep essing and prove that all of the water contained in the libre cannot be removed by heating. Another factor is the high cost of uniform drying of the Wood.

2. During impregnating:

of the wood have propess like boiling,

After the pores been opened by a special steaming, etc.,the solution of dyestuifs or impregnating substance vis forced into the Wood through hydraulic pressure and the Wood is then dried. This process ing the Wood there remains has the disadvantage of oversaturatfstructure with dyestul", i. e., far more dyestuff in the structure than is really precipitatediu the libre for the purpose o the additional diS'a f dyeing. This cleads'to dvantage that during the subsequent pressing thebre does not stick together any more and swells in water. Besides, dyestutl's are expensive, and this process is therefore not economical.

T he object of the present invention is a. process which eliminates all of these dis,- advantages by employing the pressing, impregnating and drying process in a manner which differs from the usual processes as to time and quantity and uses'a device which is specially adapted to this process. The process is characterized by the fact that the wood which does not need to be dry for pressing is mechanically pressed, mechanically held and in this condition either impregnated or chemically transformed through moist heat and the contents of moise ture removed by drying or simultaneously impregnated.

The undried or slightly dried or steamed wood is dyed in the solution as usual, with or without hydraulic pressure according to the quality of the wood and either cold or while heating or boiling or subjected to an impregnating process with hardening substances. y

The dyed (impregnated) wood is then compressed while still wet and cold or heated.. This results in a twofold advantage: The wood is still sufficiently soft in its damp or steamed condition that pressing is possible without any high pressure and without any subsequent fibre tension and furtl'iermore it is possible to press out and regain the natural moisture of the wood and the excess of dyestud solution or impregnating substance. There is only enough dyestuii' or impregnating substance left as needed for natural dyeing or hardening of the fibre.

lf no dyeing is desired and naturally colored wood used, the process changes only in regard to the quantity of the impregnating substances used. In this case green or air-dried wood can be employed out of which the sugar containing sap is pressed This sap can be utilized in case of wood. with large" contents of sugar, like birch,

The mechanical pressing is carried out by means of a device as shown 1n Figures 1 and 2 of the drawing.

stamp pushed forward.

lll

Fig. 1 is a sectional view of the device with the stamp pulled back, and Fig. 2 a. sectional view of the same device with the Fig. 3 is a cross section and Fig. 4 a longitudinal section of' a metallic form. i

The wood t be pressed, e. g., round plates 6, is led by meanseof a feeding device 3 towards the entrance of the pressing form 1 and vpressed by stamp 2 into the pressing form and through it in the direction of the ".lhe wood to be pressed is cut in such a; manner that its direction of liber coincides with the axis of the pressing form and the stamp 2 presses one of the end grains. The pressure taking place through the pressing form vertically in the direction of thelibre linds little resistance owing to the peculiar construction of the vessels and compression and removal. of the excess fluid is possible at very slight pressure. On the other end of the pressing form 1 metal .rings 7 are fed forward by a. feed disc l'into which the wood to be pressed is forced, Fig. 2, so that the wood is completely tight and unable to expand or change its form so long as it is surrounded bv the rings. is a tube,

into which enter they pieces of wood, if they are not led away by the feed disc 4. In this p tube the various form pieces of wood acpansion.

cumulate, while its wall prevents their ex- Tube 5 serves 'therefore as resistance in radial direction. I

As the wood has the tendency to expand again immediately after pressing it must be forced into a firm holder in order to produce a permanent form by compression. The wood is immovably held by means of rings or other holders and accessible onl at the end grains; it can therefore be sub]ected to instance mechanical or hydraulic presses can be used which exert direct pressure in the direction of the 'bre. If these presses are employed, it is necessary that the pressed wood pieces are immediately pressed into the rigid cover when in the final position.

The pressing process is followed by giving the final form which can be done by drying or by means of chemical processes for hard ening and stiffening the fibre. In many cases impregnationV by means of a water repelling substance will be required. The common characteristic of all these processes as applied to thepresent process is that they are. carried out on pressed pieces of wood which are immovably held in the rings.

llardening is accomplished in moist and hot air o-r steam. The wood swells, probably while undergoing chemical transformations, into a homogenous whole which is capable of great .resistance in regard to further swelling and waterproofing will be unnecessary. If hardening is carried out without any rings, no hardening takes place but the pieces of wood expand again to their original size before pressing and even beyond that which proves that the mechanical hold during pressing is an absolute requisite of the process.

If the hardening has suiciently progressed, the remainder of the moisture is removed through subsequent drying. The use of .holders permits drying without any danger of cracking orcontraction. After dryving the pressed pieces of wood have been somewhat contracted by losing their last bit of moisture and can be taken out of the rings without any diiculty or drop out antomatically.

The process permits in a simple and cheap manner by using a very simple, automatic pressing machine the wholesale manufacture of a. large number of bone-like articles. The process is specially adapted for the manufacturev of s uch articles as buttons, electrical articles, etc.

Pressing can `also be done in metallic forms. A process of this kind'is shown in Figs. 3 and 4. Fig. 3 shows the. device in cross section while Fig. 4 shows a' longitudinal section. 8 are'supports on which havebeen placed the cast-iron boxes 9. The pieces to be pressed .6 are put into the boxes from above. The boxes are thenclosed on top by means of` the presser plate 10. On the latter pressure is exerted by any pressingvdevice like 14; the box 9 has openings 12 through which the wedges 13 are put to hold down the wood -in pressed condition. (Fig. 4 to the right.) The sides of the box which lie close to the end grain of the wood are equipped with openings 15 through A which the moisture can escape. If the wood' is held down by means of the wedges 13, the pressure from above can be released and the box takenf from the support 8 to be subjected to further processes.

Having now described my invention and how the same may be performed what I claimiand desire to secure through Letters Patent is A process and device for the manufacture Y of pressed pieces of wood which is pressed in dry or moist air by means of pressi forms and pressing stamps and immediate y after lim 4compression famed nte'tuhes to prevent exmoved `from' the' rings until they have b'e- 10 pension; the said process and devibeing .come perfectly dryland hard. charaeterzed by the fact that the wood, in In testllpony w ereof I have myform of vshort ieces, is pressed into rings slgnature 1n presence of two wltnesses. and the indiv' ual pieces of wood wthln we rin am mated from the outside Y f FRITZ PFLEUMER- (throng the end grains) with hot air or Witnesses: v steam for the purpose of hardening them', D. A. ULvmg and that the sald piecesof wood are not red FRED W. WINxImR. 

